TopargeeFlush Mount Water Tank Gauge - Real-Time RV, Caravan & Boat Accessory Water Level Monitor - Accurate Flow Meter (Liter/Gallon) - Backlit LCD Display - Easy Install, No Tank Insertion Required

My trailer fresh water sensor has failed and always shows empty so I needed something to show me how much water I've used. From experience I know that I use about 10 gallons per day but would find myself running out of water unexpectedly. This device installed easily and it appears to be fairly accurate. I've only used it for one camping trip, so I'll know more next time. It's great to know how many gallons of water I have left. The only thing is that for the money the company could toss in the adapter required for connecting the hose. It would be nice if they'd include a template for cutting the hole as well.

Recently installed in one of my water tanks. Works as expected.

I bought 2 of these for my boat, one for each water tank. There are 2 bits of information that are missing in the description that would have been helpful to know up-front.First, the wiring harness from the sender unit to the display is quite short and cannot be extended with normal wires but instead you have to buy fixed-length harness extenders. I don't know why or whether it would work if you extended them normally and the instructions don't say - they just say it will void the warranty.The second point is that I was originally going to mount them at my display console (until I discovered the harness extension issue), however, after testing the display I discovered that it lights up in bright blue (there is no dimmer or "off" setting) whenever there is flow detected through the sensor. So, in the end, I installed them near the sender unit where the bright blue display would not distract my eyes to the console every time someone runs water.In limited testing so far (2 tank cycles) they are pretty accurate (within about 2%) and certainly accurate enough for my needs.A feature I think would be good would be the ability to set a "low water alarm" at a user-defined number of litres/gallons, where there is an audible alarm and perhaps the display turns orange instead of blue at and below that limit.They were easy to install and are unobtrusive and although they're a little expensive for what they are I'm happy with them since I no longer have to open the inspection hatch to guess how much water I have left.

I see now, after closer review, that this device (sensor) has male 1/2" male BSP threads. How do I connect to my water pump output that has 1/2" NPT threads?

It's scary that the first step of the install instructions ask you to cut the connector off the power supply leads and connect them to power. That is, before you've verified that the product works, they want you to modify it in a manner that prevents you from being able to return it...Fortunately for me, it just worked. Sympathy for anyone who received defective product that didn't just work after this modification. It would make much more sense for manufacturer to supply a mating connector with bare leads that the customer could connect directly to power IMHO.The other "glaring" problem with this product is that the viewing angle for the display unit is very low. Combined with the fact that most plumbing connections are located in lower cabinets and the short leads prevent installing the display unit in an upper cabinet, which implies you'd need to get on your hands and knees to read the display. I ended-up installing my display unit sideways, to work around this, but not everyone is going to want to do this.Instructions recommend that you connect power to the pump supply. I skipped this and wired directly to a constant on power supply (propane detector) because we routinely turn off power to the pump whenever we aren't in the trailer. That, and I'm not sure how long the unit would maintain it's current settings with power removed.Also, after following all other instructions, I find that the volume units displayed by the product are about 800ml each with no ability to calibrate. Not a showstopper by any means, but would be nice to be able to calibrate the product to liters or gallons or any other unit that makes sense (i.e. tank percentage).All that said, I expect that this product will enable us to enjoy our extended boondocks more with one less thing to worry about - happy trails folks!